1. Field of the Invention
The present invention relates to a zoom lens.
2. Related Background Art
There is a conventionally known zoom lens of a positive, negative, positive, and positive 4-group type. This zoom lens of the positive, negative, positive, and positive 4-group type is composed of the following four lens groups arranged in the order from the object side: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; and a fourth lens group having a positive refracting power, and is configured so that, with a change in a lens position state from a wide-angle end state (a state in which the focal length is the shortest) to a telephoto end state (a state in which the focal length is the longest), a space between the first lens group and the second lens group increases, and a space between the second lens group and the third lens group decreases, and during focusing the second lens group moves to the object side (e.g., cf. Japanese Patent Application Laid-open No. 2005-181556).